John Pitcairn Mackintosh, served East Lothian and Berwickshire as Labour MP from 1966 until 1978, when a tumour ended his life at the age of 48.

As MSP for East Lothian I daily meet people who remember him with an affection most politicians can only dream of. Some he helped, like the mother who lost a son in a tragic accident, the farmer whom planners had stopped rebuilding the family home destroyed in wartime, or the nurse appointed to a Health Board which tried to ban her because only doctors were allowed.

Others he inspired included a young farmer who heard Mackintosh speak in Paxton village hall in 1970. John Home Robertson joined the Labour Party on the spot and in 1978 he succeeded Mackintosh in a by-election Labour was supposed to lose.

While an MP, Mackintosh was also professor of politics at Edinburgh University and a distinguished columnist, not least for The Scotsman. His friend David Marquand described him as an “endangered species, activist academic and reflective practitioner of politics”.

In one essay, Mackintosh described his interest in politics as “obsessive”. He loved all of it – the theory, ideas, machinery, practice and gossip – of politics. There are echoes of “praxis” – the Marxist idea of theory and action united. But Mackintosh was no Marxist. On Labour’s social democratic wing, he conspired, badly, for a Roy Jenkins leadership, and consequently never held office under Wilson or Callaghan.

It would be easy to imagine a patrician MP, distant from constituency and local Labour Party, but nothing could be further from the truth. Perhaps there was little in common between the miners and construction workers who were the backbone of the party, and the privately educated academic, but when Mackintosh defeated the odds, and the sitting Tory, in 1966, the local party knew they had a winner. Party and politician drew strength from each other. When he lost the seat in February 1974, they simply fought back together and retook it in October.

Another much loved Labour figure, Gerald O’Brien, was Mackintosh’s agent. He claimed that in 12 years, Mackintosh missed only one constituency party meeting, and that was because Gerald forgot to put it in his diary. At a time when most MPs didn’t even hold surgeries, East Lothian Labour Party somehow acquired a caravan, and Mackintosh worked the towns and villages of his rural constituency every weekend.

Mackintosh enlisted the local party in the great campaigns of his life, Europe and devolution. He first made his arguments for devolution at Labour conference in 1958, and advanced them relentlessly in the Commons, through columns and to Royal Commissions. But he tested and perfected them in public debates in the Labour clubs and village halls of East Lothian.

This was a tradition he believed in, once writing wistfully: “Gladstone had no hesitation about speaking for two hours to assembled villagers about the complexities of the Eastern Question.” He, too, had the eloquence not just to articulate the case, but to move his audience with it.

Thus the devolution flame was kept alight through years when it was anathema to the Labour leadership. When it became party policy in 1974, it was on the back of a conference resolution from East Lothian. Mackintosh’s death spared him the pain of the 1979 devolution debacle, but robbed him of the final satisfaction of seeing the parliament created in 1999.

To read Mackintosh now is to be astonished at his prescience. Holyrood is recognisably the parliament he designed decades ago, right down to its responsibilities, committee structure and tax powers.

Mackintosh scorned the idea of devolution as a response to the SNP “threat”. His argument was for better government. He believed that the “Westminster model” no longer held power to account, and in particular that the Scottish Office ran Scotland’s health, law and education systems without democratic oversight. He wrote that “Scottish Government must reform government”, adding that it must be “more effective, cheaper and more responsive to the Scottish public”.

Mackintosh always had sympathy for nationalists, but he thought they were fundamentally wrong, because identity was the core of their politics. Mackintosh believed that most Scots felt both Scottish and British, and that a devolved parliament best reflected this reality.

In an exchange with the late Stephen Maxwell of the SNP, who accused him of denying his cultural identity because he spent too much time with his “peers in English politics”, he coolly responded: “We have only to… add a European dimension to the dual nationality to fit the realities of modern political life.” Of course, the SNP was staunchly anti-European at that time.

Mackintosh considered himself a devolution “maximalist”, but argued that some things like pensions are more secure when pooled across the larger economic unit. He thought that a Scottish Parliament would “excite the Scottish people” and “unleash their constructive energies”. As for devolution as a “slippery slope” to separatism, he wrote: “All the evidence from other countries shows that once a generous degree of decentralisation has been conceded, the virtues of remaining part of a larger unit become much clearer.”

Now, in the heat of the referendum debate, is that not what has happened? When the SNP tell us that we will be independent but keep the pound, the Bank of England, UK-wide financial regulation, open borders with England, the protection of Nato, MoD contracts in our shipyards and the BBC on television, are they not simply conceding that the virtues of the larger unit are clear?

Equally, when SNP thinkers like Andrew Wilson say “we have all outgrown identity politics now”, and suggest we can be independent, but still be British, are they not admitting that Mackintosh’s “dual nationality” is the reality for Scots? To this we can add the desperate attempts to assert, without evidence, that the European dimension will not be lost.

And when Alex Salmond celebrates “his” achievements of 2,000 days as First minister, is he not demonstrating that devolution has indeed worked, unleashing our constructive energies?

So, Mackintosh’s arguments for devolution resonate strongly the referendum debate today, but, ironically, in the SNP’s efforts to turn them on their head. It is time Labour took them back and turned Mackintosh right side up. After all, Mackintosh believed the greatest threat to devolution was the timidity of devolutionists. Labour should argue unashamedly that a strong Scottish Parliament in a quasi-federal UK is the right, authentic reflection of the reality of Scots’ dual nationality.

We should shout about the virtues of remaining part of a larger unit, and expose as fraudulent the SNP’s attempts to pretend they can survive separation. Most of all, Labour should reclaim the parliament itself and the achievements of 13 years of constructive energies unleashed. Mackintosh made the case for devolution; his arguments can help us save it.

In the parliament he never saw, Mackintosh’s words are carved: “We have people in Scotland who want a degree of government for themselves at the Scottish level. It is not beyond the wit of man to devise the institutions to meet those demands.” Exactly.